This invention relates in general to pressurized dispensing and in particular to actuators for tilt valves used in aerosol containers.
A wide variety of actuating devices have been used in aerosol dispensers having tilt actuated valves. Examples are: devices in which direct finger pressure is applied to the valve stem in a direction normal to the stem, such as the devices shown in U.S. Pat. Nos. 2,615,597 and 2,992,760; devices having a trigger piece fixedly attached to the valve stem and designed to be laterally displaced to tilt the stem, such as the device shown in U.S. Pat. No. 3,583,607; devices in which a trigger piece is arranged to be laterally displaced to contact and laterally displace the valve stem, such as the device shown in U.S. Pat. No. 3,236,421; and extension devices fixedly attached to the valve stem and providing a depression point laterally offset from the stem whereby the stem tilts toward the point of depression, such as devices shown in U.S. Pat. No. 3,330,447.
None of these types of tilt actuating devices are at all similar in operation or appearance to the well-known actuator-overcap of the type used with aerosol valves of the type requiring stem depression (as opposed to stem tilting) for actuation. Such actuator-overcaps typically have a main portion which is attached to the pressurized container and a tab or button portion which when axially depressed actuates the aerosol valve. Consumers of aerosol products are well acquainted with this sort of device and can operate it without need for instructions. On the other hand, many actuators for tilt valves are either not well known and/or do not lend themselves to packaging which is aesthetically pleasing or in keeping with traditional package configurations for certain product lines.
This invention provides a unique actuating device for use with pressurized dispensers of the type having tilt actuatable valves. The device of this invention includes a main or overcap portion adjacent the pressurized container and a finger-depressible tab or actuator portion hinged at one end to the main portion and having its other end adjacent the valve stem such that the stem may be tilted by the tab portion to actuate the valve when the tab portion is axially depressed. The actuator-overcap device defines an access opening to receive the valve stem. In preferred embodiments the access opening is defined in the tab portion near a free end of the tab portion (that is, the end remote from the hinge). When the access opening is defined in the tab portion, it is aligned with the stem axis when the tab is not depressed and mis-aligned therewith when the tab is depressed, thereby to tilt the valve which is received in or entrapped in the access opening. In preferred embodiments the hinge of tab portion to main portion is at the radial perimeter of the main portion and the distance from the hinge to the free end of the tab portion, in a direction normal to the stem axis, is greater when the tab is depressed than when it is not depressed. In some preferred embodiments the end of the valve stem is recessed within the access opening. If a spray is to be discharged, a spray member having an axially directed spray orifice is attached to and forms part of the valve stem within the access opening, and interacts with the tab portion when it is depressed.
This invention provides a device for actuation of tilt valves which may be easily understood by consumers because of its similarity in operation to the well-known actuator-overcaps used with aerosol valves of the type actuated by axial depression of the valve stem. This invention also provides an actuator-overcap for use with tilt-actuated valves which lends itself to a variety of aesthetically pleasing designs, including designs traditionally used in actuator-overcaps for certain well-known products.
This invention is extraordinarily easy to operate -- requiring application of very light finger pressure in comparison with many commonly used valve actuating devices. This benefit is made possible in part by a mechanical advantage derived through the small angle of interacting convergence between the tab portion and the stem. Specifically, the mechanical advantage is inversely proportional to the sin of the angle of convergence of tab with stem and directly proportional to the fraction between 0 and 1 which is representative of the location of the point of force application on the tab. Force is applied somewhere between the hinge and the effective end of the tab portion. If the pressure point is at the effective end, the fraction is 1; if the pressure point is at the hinge, the fraction is 0; if 2/3 of the way from hinge to effective end, the fraction is 2/3; etc. Provided, for example, that finger pressure is applied midway between the hinge and the point of contact between tab portion and valve stem, and provided further that the angle of convergence is 15.degree., a mechanical advantage of about two is obtained, assuming factors such as friction to be negligible. That is, if the axially applied force is X, a force of about 2X is exerted by the tab portion on the valve stem. A greater or lesser advantage could be obtained by changing the pressure point and/or the angle of convergence.